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Photosynthesis Lab – Measuring the Rate of Photosynthesis

Purpose
Observe photosynthesis in an aquatic plant.
Measure the rate of photosynthesis by Elodea plants.

Materials
1000-ml BeakerTwo Elodea plants
Colored cellophane
Lamp
0.25% sodium hydrogen carbonate solution (baking soda)
Stop watch

Procedure
1. Place the Elodea plants in the beaker and cover them completely withwater. Add some of the baking soda solution. The solution provides CO2 for the Elodea. Record the time.
Be sure to use the same amount of water and solution for each trial.
2. Conduct acontrol by directing the lamp (without colored cellophane) on the plant and noticing when you see the bubbles. Record the time.
3. Observe and record the number of oxygen bubbles that Elodeagenerates in five minutes.
4. Cover the lamp with a piece of colored cellophane and repeat steps 2 and 3.
5. Repeat steps 2 and 3 with a different color of cellophane.
6. Record all data inthe table below.

Data Collection

| |Control (no |Color 1 |Color 2 |Color 3 |
| |cellophane) || | |
|Time when bubbles | | | | |
|first appeared || | | |
|Bubbles observed in | | | | ||five minutes | | | | |

Results & Conclusion

Rate of photosynthesis = number of oxygen bubblesTime

1. Calculate the rate of photosynthesis in # of bubbles per second.

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